ABSTRACT

This chapter presents an account of the three nuclear fuel materials—uranium (U), plutonium (Pu), and thorium (Th). The fissioning process for the nuclear fuels takes place within the core of a reactor. This is the main event of the nuclear power. There are, however, a number of other important events that take place for the nuclear fuels, both before and after their sojourn in the core. Two fuel cycles form the basis for the utilization of nuclear energy: one with plutonium as a part of the cycle is called the U-Pu fuel cycle, and the other, with thorium exploited for generating fissile U, is called the Th-U fuel cycle. The relationship between the thermal and fast breeder reactor systems which the fuel cycle, as given above, projects is bound to remain in nuclear energy production. The tail-end of the nuclear fuel cycle encompasses all activities following discharge of the nuclear fuel after concluding its permissible useful service in the reactor.